#!/usr/bin/env python3
# -*- Coding:UTF-8 -*-
#  14:31
import requests


class SessionTool(object):

    _s=None

    @classmethod
    def get_session(cls):
        if cls._s==None:
            cls._s=requests.Session()
        return cls._s

    @classmethod
    def close_session(cls):
        if cls._s:
            cls._s.close()
            cls._s=None


if __name__ == '__main__':
    s=SessionTool.get_session()
    print(s)
